On this screen, make sure that only the following buttons are enabled: Import Animation, Import Extra Skeleton Nodes As Bones,Import Skeleton Only + Parent Selected, Realign Bone Tail Only, Merge Skeleton Roots

In the Keyframe File, browse to the animation file you want by clicking on the ... button

Click OK

Hopefully the animation will import properly with the animation.

Note 1: You have to import animations by merging with a file, you cannot apply an animation to an armature that has already been imported! You need to apply copy location and rotation constraints to an existing armature to shadow the imported armature if you want to do this. I'm busy writing a script to do this setup quickly, which will be added to the updated animation kit mentioned above for the next update.

Note 2: Also, if you try to "zoom to object" (the "." key on the keypad), the armature will normally disappear. This is because some of the bones don't have proper values set in the animation files. The bones that typically cause this are the hands, finger, pauldron and wrist & arm twist helper bones. If these bones look odd, or you cannot find them, then you need to select them (using the Outline view) and remove/reset the translation, rotation and scaling IPO curves. Zooming should work again after this.